Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-29T08:31:16Z No. of bitstreams: 2 Dissertação - Carlos Henrique Pereira - 2014.pdf: 3850945 bytes, checksum: 985b041e7a863070b3fa0562180a40f3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-01-29T08:33:08Z (GMT) No. of bitstreams: 2 Dissertação - Carlos Henrique Pereira - 2014.pdf: 3850945 bytes, checksum: 985b041e7a863070b3fa0562180a40f3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-01-29T08:33:08Z (GMT). No. of bitstreams: 2 Dissertação - Carlos Henrique Pereira - 2014.pdf: 3850945 bytes, checksum: 985b041e7a863070b3fa0562180a40f3 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-07 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Objective: Investigate, on a comparative basis, the expression of the adhesion molecules E-cadherin (E-cad), β-catenin (β-cat) and the proliferation index (Ki-67) at the invasive tumor front (ITF) in Squamous Cell Carcinoma (SCC) and basaloid squamous cell carcinoma (BSCC). Material and Methods: Thirty-five SCC and 16 BSCC cases were evaluated by immunohistochemistry. Clinico-pathological data and survival data were evaluated and compared. Results: There was a low expression of E-cad in the cytoplasmic membrane (p = 0.50) as well as in the nucleus (p = 0.31) for both SCC and BSCC. A high expression of E-cad was seen in the cytoplasm for the SCC group (80%) when compared to the BSCC group (25%) (p<0.01). The expression of β-cat in the cytoplasmic membrane (p = 0.28) and in the cytoplasm (p = 0.44) was low in both SCC and BSCC groups. Both types of carcinoma presented low expressions of β-cat in the nucleus (p = 0.03). The Ki-67 expression was low irrespective of tumor variant. The high expression of E-cad in the cytoplasm was associated with T3/T4 tumors (p = 0.04) in the SCC group and there was no significant association of E-cad, β-cat, Ki-67 with the other clinical variables. In terms of disease-free survival and overall survival, there were no significant differences between SCC and BSCC. Conclusion: The E-cad-β-cat system was found to be dysregulated in both oral SCC and oral BSCC. The Ki-67 cell proliferation index was extremely low in the cases investigated and consequently had no prognostic value. / Objetivo: Investigar comparativamente a expressão das moléculas de adesão E-caderina (E-cad), β-catenina (β-cat) e o índice de proliferação (Ki-67) em Carcinoma Espinocelular (CEC) e Carcinoma escamoso basalóide (CEB). Material e Métodos: Nesse estudo, foram selecionados 35 casos de CEC e 16 casos de CEB e investigados por meio de técnica imuno-histoquímica. A associação das variáveis clinico-patológicas e dados de sobrevida foram avaliados. Resultados: Ambos os grupos tiveram baixa expressão de E-cad em membrana citoplasmática (p=0,50) e núcleo (p=0,31), essa associação não foi estatisticamente significante entre os grupos. Alta expressão de E-cad no citoplasma foi notada no grupo CEC (80%) quando comparado ao grupo CEB (25%), p<0,01. A expressão de β-cat em membrana citoplasmática (p=0,28) e citoplasma (p=0,44) foram baixos em CEC e CEB. Ambos os grupos tiveram baixa expressão de β-cat em núcleo, p=0,03. Não houve diferença estatisticamente significante quanto à expressão de Ki-67 entre os grupos. Alta expressão de E-cad em citoplasma foi associada a tumores T3/T4 (p=0,04) no grupo CEC. Pacientes estilistas apresentaram baixa expressão de β-cat em membrana citoplasmática (p=0,05). Não houve associação entre a expressão de E-cad, β-cat e Ki-67 com as demais variáveis clínicas dos grupos. A sobrevida livre de doença e a sobrevida global não foram estatisticamente significantes na associação entre os grupos CEC e CEB. Conclusão: O sistema E-cad-β-cat encontra-se desregulado tanto nos de CEC quanto nos de CEB de cavidade oral, levando as células epiteliais a perderem o seu fenótipo e promovendo a invasão e progressão tumoral. O índice de Ki-67 foi extremamente baixo não tendo valor prognóstico nos casos avaliados.

Les carcinomes épidermoïdes des voies aéro-digestives supérieures (VADS) se situent au sixième rang des cancers les plus fréquents dans le monde. Ces tumeurs sont liés à deux facteurs de risque : l’intoxication éthylo-tabagique (80% des cas) et l’infection de l’épithélium des VADS par les papillomavirus humain (HPV) à haut risque oncogène (20% des cas). Ces derniers définissent une sous-population de patients de meilleur pronostic. Une des hypothèses actuellement étudiées, afin d’expliquer la survie améliorée des patients HPV positifs, serait une hypoxie moindre dans ces tumeurs. En effet, les tumeurs des VADS sont fréquemment hypoxiques, et l’hypoxie intratumorale est un facteur de mauvais pronostic. Dans une première partie de cette thèse, nous avons entrepris une caractérisation moléculaire de l’hypoxie intratumorale dans les tumeurs humaines oropharyngées en fonction du statut HPV. Il apparaît que les tumeurs HPV positives présentent un statut hypoxique moindre comparées aux tumeurs HPV négatives. Ces tumeurs se caractérisent également par une abondante vascularisation intratumorale, qui pourrait être à l’origine de ce statut hypoxique moindre. Dans une deuxième partie, nous avons étudié l’adaptation à l’hypoxie de la lignée cellulaire HPV négative SQ20B et la lignée cellulaire HPV positive SCC90. De plus, des modèles de xénogreffes ont été établis à partir de ces mêmes lignées cellulaires et ont été analysés du point de vue de l’hypoxie intratumorale. De façon comparable aux tumeurs HPV positives, les xénogreffes obtenus à partir de la lignée SCC90 montre un statut hypoxique réduit comparés aux xénogreffes SQ20B. Les deux lignées cellulaires s’adaptent également différemment en hypoxie in vitro. La réponse à l’hypoxie dans la lignée SCC90 semble plus dynamique. En effet, la lignée SCC90 tente de s’adapter et de répondre à cet environnement hypoxique en induisant de fort niveau d’expression de gènes comparée à la lignée SQ20B. / Head and neck squamous cell carcinoma (HNSCC) represents the sixth most common malignancy worldwide. The major risk factors for HNSCC identified are tobacco use and alcohol consumption (80% of all HNSCC), which seem to have a synergistic effect. A subgroup of HNSCCs (20% of cases), particularly those of the oropharynx, is caused by infection with high-risk types of human papillomavirus (HPV). Human papillomavirus HPV-related oropharyngeal squamous cell carcinoma defines a distinct clinical subgroup of head and neck cancer patients with improved prognosis. Currently, one of the several hypothesis studied to account for their improved survival outcomes could be a distinct hypoxia status compared to their HPV-negative counterpart. Indeed, tumour hypoxia is common in solid tumours including head and neck tumours, and hypoxia is a well-known poor prognosis factor. In first part of this thesis, we have performed a molecular characterisation of tumor hypoxia on cohort of oropharyngeal tumours according to HPV status of the patients. The results support the hypothesis that HPV-related tumours display a lesser hypoxia status compared to HPV-negative oropharyngeal tumours. These HPV-related tumours also characterize by an abundant tumour vascularisation, which could be responsible for a lesser hypoxia status. In a second part, we have studied the ability of the adaptation to hypoxia of the HPV-positive SCC90 cell line and HPV-negative SQ20B cell line. Furthermore, HPV-positive and HPV-negative HNSCC xenograft models have been established and have been analysed about tumor hypoxia. Similar to HPV-related HNSCC, tumours-derived HPV positive cell lines display a reduced hypoxic status compared to tumours-derived HPV negative cell lines. The two cell lines adapt also differently to in vitro hypoxia. In the HPV-positive cell line, the hypoxia response pathways could be more dynamics. Indeed, SCC90 cell lines attempt to adapt and to reply to hypoxic environment inducing highly expression of all of the hypoxia related genes compared to SQ20B cell lines.

No description available.

published_or_final_version / Pathology / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Molecular Biology / Master / Master of Philosophy

published_or_final_version / abstract / Medicine / Master / Master of Philosophy

published_or_final_version / abstract / Pathology / Doctoral / Doctor of Philosophy

published_or_final_version / Surgery / Master / Master of Philosophy

published_or_final_version / Surgery / Doctoral / Doctor of Philosophy

Background: Oral Tongue Squamous Cell Carcinoma (OTSCC) is the most frequent and aggressive carcinoma in the head and neck region. Its incidence has increased during the last decades, especially in young patients (≤40 years) mainly female. These young patients have either not been exposed to the traditional risk factors for this disease, or have a much reduced duration of exposure than the typical OTSCC patient. The reasons behind this increasing incidence remain unknown. The aims of this thesis were to analyse the presence and possible role of human papillomavirus (HPV) in oral tongue cancer in correlation with its surrogate marker p16 and its receptor syndecan-1. Other aims were to evaluate expression of EMT (epithelial to mesenchymal transition) - related markers, such as E-cadherin, β-catenin, CK5 and CK19, and to address the potential predictive role of podoplanin in the loco-regional metastatic process. Clinical parameters including age, sex, geographical distribution, relapse, tumour staging and grading were also investigated for a possible correlation with biomarker expression and prediction of survival rate and therapeutic strategy. Materials and methods: More than one hundred samples of OTSCC coming from two University Hospitals of two different countries (Sweden and Italy) were analysed. HPV presence was evaluated by in situ hybridisation for detection of the high-risk HPV 16 and indirectly by immunohistochemistry (IHC) of its surrogate marker p16. Expression of the HPV receptor syndecan-1 and the EMT biomarkers E-cadherin, β-catenin, CK5, CK19 were also evaluated by immunohistochemistry. Samples were scored using a quick score (QS), taking both number and intensity of cells stained into account. Podoplanin expression was investigated at both protein and RNA level. Results: Tumour size and lymph node metastasis correlated to both overall and disease-free survival. Despite variable expression of the syndecan-1 receptor, HPV 16 was not detected in any sample analysed, excluding a possible association with p16, which was expressed in 33% of the cases. All EMT-related markers were commonly expressed in tongue cancer. Data showed E-cadherin to be an independent prognostic factor with higher expression associated with poor overall survival. Notably, E-cadherin, β-catenin and CK5 directly correlated to each other. Multivariate analysis of clinical data demonstrated that age of the patient is an independent prognostic factor with younger patients showing a worse survival rate. Patients younger than 40 years also showed significantly higher expression of podoplanin. Data for geographic distribution revealed a difference in expression of E-cadherin between Swedish and Italian patients. Conclusions: In contrast to SCC of the base of the tongue and the tonsil, HPV is not present in OTSCC, excluding HPV infection as a risk factor. Higher levels of E-cadherin and young age is associated with poor survival in OTSCC patients. The different frequency of EMT markers seen between Swedish and Italian patients suggests an important role for the environment and the geographical area in the onset of different molecular patterns of OTSCC.